Generally, a navigation system includes a map display apparatus. The map display apparatus displays a necessary map on a display portion such as a display unit and displays the current vehicle position overlapping with the map to provide the guidance.
Therefore, the navigation system stores display map data to display the map. The display map data includes background data to draw buildings or landforms, road data to draw roads, and character data to draw names of buildings or roads.
Drawing characters using the character data allows a user to confirm facility names, enabling to provide proper guidance. Recently, various proposals are made to draw characters using character data. For example, a proposed apparatus prioritizes character data to prevent drawn characters from overlapping and draws a character based on highly prioritized character data if display positions overlap (e.g., see Patent Literature 1).